Method of separation of granular materials



' May 16, 1933.

qventor, 3 I

Dever Campbell Ashmead B) 9671/ Attorney D. c. AAAAA AD 1,909,159

. May 16, 1933.

D. c. ASHMEAD METHOD OF SEPARATION OF GRANULAR MATERIALS Filed Nov. 28, 1930 4 Sheets-Sheet 2 I I l I Inventor Dever Ce impbellAshmead Umuf. Attorney May 16, 1933. Q ASHMEAD 1,909,159

METHOD OF SEPARATION OF GRANULAR MATERIALS Filed Nov. 28, 1930 4 Sheets-Sheet 5 Inventor,

Dever C ampbellAshmead B) W1 llome y.

May 16, 1933. c ASHMEAD 1,909,159

METHOD OF SEPARATION OF GRANULAR MATERIALS Filed Nov. 28, 1950 4 Sheets-Sheet 4 Inventor, v

Dever C am beHAshme aEl Attorney the conveyor for skimming an Patented May 16, 1933 I umrED STATES PATENT OFFICE J DEVER CAMPBELL ASHMEAD, OF KINGSTON, PENNSYLVANIA, ABSIGNOB OI ONE-HAL! 1'0 GEORGE WASHINGTON WILMOT, OF HAZLE'ION, PENNSYLVANIA, AND ONE- I'OUBTH '10 EDWARD WELLES, JR., OF wlLxEs-BARRE rENNsYLvANIA IETEOD OI SEPARATION OF QBANULAR MATERIALS Application nled November 28, 1980. Serial 110. 498,848.

The ob'ect of this invention is to provide for t e efiicient separation of granular materials having a difference in specific gravity, such as crushed coal and slate, or metal ores and the gangues with which they are associated. Such separation is effected in a settling tank through the medium of a li uid of intermediate specific gravity. Suc liquids are expensive, and a further object is to prevent wastage of such liquids in order that the method may be carried out economically on a commercial scale. Also such liquids have volatile components that contaminate the air if permitted to escape, and a further object is to prevent such volatllization. 1

In the accompanying four sheets of drawings which form a part of this description Figure 1 is a to view of a materials separating tank which embodies this invention.

Fig. 2 is a vertical section through the tank on the line 11-11 of Fi 1 showing discharging the floating materials from this tank.

Fig. 3 1s a'verticaI section through the tank on the line III-III of Fig. 1 showing the conveyor for removing and discharging the settled materials from this tank.

Fig. 4 is a side elevation showing one of the shaking screens, one of the liquor separating tanks, and the circulating system.

Fig. 5 is an end view of the same showing both screens and tanks.

Fig. 6 is a vertical section on the line VIVI of Figs. 1, 2 and 3, drawn to a larger scale.

As shown, the materials to be separated are first passed down an inclined screen 10 and subjected to a light water .spray from a spray pipe 11. By spraying the materials while tumbling down this screen, any adhering grains are brokenapartand complete wetting of their surfaces is insured. Any dirt is washed away and grains too small for economical treatment are also removed by the spray water which is discharged since it carries too much dirt for reuse or after use in the other parts of the apparatus. It has been found practical to economically treat material larger than fifty mesh.

From this screen, where the materials have been given a preliminary spraying, they are discharged into the first of two com artments of a materials separating tan 12 through a water seal 13 and into a liquor 14 of which the specific gravity is intermediate of the specific ravitiesof the materials to be separated. he water seal is conveniently of a depth u to about eighteen inches.

for the separation of coal and slate the liquid is chiefly acetylene tetrachloride or carbon tetrachloride. A perforated inclined apron 15 extends from a point just below the level of the liquor and out over the top of the tank. The tank extends under the apron. A scraping conveyor with chains 16 and scrapers 17 lead across the tank at or near the level of the liquorand along the apron. To lessen wear the chains are guided so that the scrapers will be held just clear of the apron, and the scrapers are referably perforated so that the liquor and the water will not be carried along with the material. The conveyor skims the floating materials from the liquor and pushes them alon 'the apron and up through the water seal an discharges them at the end of the tank.

A vertical partition 18 in the tank separates its upper portion into two compart ments. It extends from a point below the level of the liquor to the top of the tank. The

partition is sufliciently perforated so that no vergin toward the second compartment which is the deeper.

In the second com artment 1s a second inclined apron 19 whic extends from the bottom of the tank and out over the top. The

upper art of this apron is perforated and the tanli extends under thisapron. A second scraping conveyor with chains 20 and perforated scrapers 21 leads from the bottom of the tank and along the second a ron similarl to the other conveyor. It pu es the settl materials up from the bottom of the tank through the water seal and dischar as them at the end of the tank separately cm the floating materials. The widths of the two compartments and of the conveyors operating in them are preferably pro ortioned to about the relative quantities of e separated materials.

A shaking screen 22 receives the light ortion of the materials and a separate s aking screen 23 receives the hea portion of the materials discharged from t e materials separating tank. A spray pipe 24 overlies the screens and projects a buy spray of water, preferably with ammonia onto the materials on these screens. The ammonia water washes off and carries with it any liquor which may have been carried over from the materials separatin the traces of liquor whic adhere to the materials as the pass off from the shaking screens to sue a point that the losses wil not render the method uneconomical.

A drip pan 25 underlies the screens and receives the ammonia water together with any of the liquor which has been washed from the separated materials. From the drip pan the ammonia wash water asses through pipes 26 and valves 27 to either or both of two liquor separating tanks 28. The level of the water is maintained inthe pipes to minimize the area ex osed to evaporation. From near the tops 0 .the liquor separating tanks the ammonia water is drawn ofi thro h valves 29 and a circulating pum 30 by w ich it is lifted to an overhead ta 32 from which it falls to the spray pipes over the shakin screens. Any .excess water in the overh tank drains through an overflow pipe 83 to the water seal in the materials separating tank. A liquor pump 34 is 0 rated as neede to return liquor from the iquor separating tanks to the materials separating tank.

A- chute 34 receives and finally discharges from the ap aratus the light separated materials from t eir shakin screen, and a chute 35 receives and finally ischar es the heavy separated materials from t eir shaking screen.

This invention is not limited to the particular apparatus shown for such apparatus may be of any of the customary types which are employed for wet separations epending on difierences in the specific gravities of the tank, and reduces avity of the li uor need not be when weighed statically o a value exactly intermediate of the materials to be separat I claim:

1. The method of separating granular materials which consists in immersing them under a water seal in a body of liquor of which s ific gravity is intermediate of the materia to be separated, skimming the floating as arated materials and draining-separately ifting the settled separated materials discharging them through the water seal an draining receivin the drip ings from the separated materia in a tan with an ammonia water seal, and circulating the ammonia water throu h a spray onto the separated materials while draining.

2. The method of separating granular materials which consists in subjecting them i to a preliminary spraying immersing them under awater seal in a body of liquor of which sgecific gavity is intermediate of the materia to separated, skimming the floating se arated materials and draining, separately ifting the settled separated materials, discharging them 'throu h the water seal and draining receiving t e dri pings from the separated materials in a ta with an ammonia water seal, and circulating the ammonia water through a spray onto the separated materials while draining.

3. The method of se arating granular materials which consists in immersing them under a water seal in a bodyof li uor consisting chiefly of acetylene tetra romide, skimmin the floating se arated materials and draining, separately ifting the settled separated materials, discharging them through the water seal and draining, receiving the drippings from the separated materials in a tankwith an ammonia-water seal, and circulating the ammonia water throu h a spray onto the separated materials while draining.

4. The method of separating granular materials which consists in immersing them under a water seal in a body of liquor consisting chiefly of acetylene tetrachloride, skimming the floating se arated materials and draining, separately ifting the settled separated materials, discharging them through the water seal and draining, receiving the drip ings from the separated materials'in a tan with an ammonia water seal,

and circulatin the ammonia water throu h a spray onto t e separated materials while draining.

5. The method of separating granular materials which consists m immersing them under a water seal in a body of li uor consisting chiefly of carbon tetrachlori e skimming the floating se arated materia and draining, separately liftin the settled separated materials, discharging them through the water sealand draining, receiving the drippings from the separated "materials in a tank with an ammonia water seal and circulating the ammonia water through a spray onto the separated materials while draining. 6. The method of separating granular materials which consists in immersing them under a water seal in a body of liquor consisting chiefly of acetylene tetrabromide and 1 acetylene tetrachloride, skimming the floating separated materials and draining, separately lifting the settled separated materials, discharging them through the water seal and draining, receiving the dri pin s from the separated materials in a ta wit an ammoni'a water seal, and circulating the ammonia water through a spray onto the separated materials while draining.

7. The method of separating granular ma- 2 terials which consists in immersing them under a water seal in a body of liquor consisting chiefly of acetylene tetrabromide and carbon tetrachloride, skimming the floating separated materials and draining, separately lifting the settled separated materials, discharging them through the water seal and draining, receivin the drippings from the separated materia s in a tank with an ammonia water seal, and circulating the ammonia water 3. through a spray onto the separated materials while draining. 1

8. The method of separating granular materials which consists in immersm them under a seal of low specific gravity liquid in a body of liquor of high specific gravity, skimming the floating separated materials and draining, separately lifting the settled separated materials, dischargmg them through the low specific gravity llqllld and draining, receiving the drippings from the separated materia s in a tank with an ammonia water seal, and circulating the ammonia water through a spray onto the separated materials While draining. DEVER CAMPBELL ASHMEAD. 

